<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>盒子模型</title>
    <style>
        .div1 {
            background-color: #eee;
            width: 200px;
            height: 200px;
            margin-top: 50px;
            padding: 10px;
            border: 1px solid #000;
        }
    </style>
</head>

<body>
    <div class="div1">
        盒子模型试验
    </div>
</body>

</html>